Questions | Answer | Explanations |
1 The gold foil experiment led to the conclusion that each atom in the foil was composed mostly of empty space because most alpha particles directed at the foil
(1) passed through the foil
(2) remained trapped in the foil
(3) were deflected by the nuclei in gold atoms
(4) were deflected by the electrons in gold atoms | 1 | atoms are mostly empty space they went right through |
2 Which subatomic particles are located in the nucleus of a carbon atom?
(1) protons, only
(2) neutrons, only
(3) protons and neutrons
(4) protons and electrons | 3 | the electrons are outside protons and neutrons are inside |
3 Which part of a helium atom is positively charged?
(1) electron (3) nucleus
(2) neutron (4) orbital | 3 | the electrons are outside protons and neutrons are inside protons are positive and neutrons are neutral |
4 The mass of a proton is approximately equal to the mass of
(1) an alpha particle (3) a neutron
(2) an electron (4) a positron | 3 | protons 1 amu neutron 1amu electron 1/1836 amu |
5 At STP, solid carbon can exist as diamond and graphite. Compared to the molecular structure and chemical properties of diamond, graphite has
(1) a different molecular structure and different properties
(2) a different molecular structure and the same properties
(3) the same molecular structure and different properties
(4) the same molecular structure and the same properties | 1 | different structures have different properties |
6 Which Group 14 element is classified as a metal?
(1) carbon (3) silicon
(2) germanium (4) tin | 4 | bottom of the group |
7 The light emitted from a flame is produced when electrons in an excited state
(1) absorb energy as they move to lower energy states
(2) absorb energy as they move to higher energy states
(3) release energy as they move to lower energy states
(4) release energy as they move to higher energy states | 3 | electrons fall to lower energy producing light |
8 An atom of which element has the greatest attraction for electrons in a chemical bond?
(1) As (3) Ge
(2) Ga (4) Se | 4 | definition of electronegativity TABLE S |
9 Which formula represents a polar molecule?
(1) H2 (3) CO2
(2) H2O (4) CCl4 | 2 | SNAP symmetrical nonpolar asymmetrical polar sketch them |
10 Two categories of compounds are
(1) covalent and molecular
(2) covalent and metallic
(3) ionic and molecular
(4) ionic and metallic | 3 | molecular mean covalent metallic is not a compound |